Heat oven to 350 degrees F. In large bowl, break up cookie dough. Stir or knead in 1/4 cup all-purpose flour until well blended. Divide dough in half; wrap each half in plastic wrap. Place in freezer 10 minutes.
Shape half of dough into 1-inch balls. With fingers, roll each ball into 10-inch rope, about 1/4 inch wide. Break off small piece from each rope for tree trunk. Carefully place ropes on ungreased cookie sheet.
With each rope, starting at top, twist rope back and forth into tree shape, gradually making larger at bottom (rows of dough should touch). If rope breaks, press dough together. Place small piece at bottom of each tree for trunk. Repeat with remaining half of dough.
Decorate trees with candies to look like ornaments or lights. Place candy at top of each tree for star; sprinkle with sugar. Bake 9 to 13 minutes or until edges are light golden brown. Cool 1 minute; remove from cookie sheets to cooling racks.
Add green food coloring to the dough, if desired.